Apollo is an enormous

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

located in the southern

hemisphere Hemisphere refers to: * A half of a sphere As half of the Earth * A hemisphere of Earth ** Northern Hemisphere ** Southern Hemisphere ** Eastern Hemisphere ** Western Hemisphere ** Land and water hemispheres * A half of the (geocentric) celes ...

on the

far side ''The Far Side'' is a single-panel comic created by Gary Larson and syndicated by Chronicle Features and then Universal Press Syndicate, which ran from December 31, 1979, to January 1, 1995 (when Larson retired as a cartoonist). Its surrealis ...

of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. This formation dwarfs the large crater Oppenheimer that is located next to the western rim. The crater Barringer lies across the northern wall. To the southeast is the crater

Anders Anders is a male name in Scandinavian languages and Fering North Frisian, an equivalent of the Greek Andreas ("manly") and the English Andrew. It originated from Andres via metathesis. In Sweden, Anders has been one of the most common names fo ...

, and Kleymenov is just to the east of the rim. Apollo is a double-ringed walled plain (or basin) whose inner ring is roughly half the diameter of the outer wall. Both the outer wall and the interior have been heavily worn and eroded by subsequent impacts, so that significant parts of the outer and inner walls now consist of irregular and incised sections of mountainous arcs. The interior floor is covered in a multitude of craters of various sizes, some of which have been named for people associated with the Apollo program or other

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

projects. Sections of Apollo's interior have been resurfaced with

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

, leaving patches of the floor with a lower

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...

than the surroundings. There is a large patch of this

lunar mare The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

in the middle part of the inner ring, which contains some

ray system A ray system comprises radial streaks of fine '' ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to several times the diameter ...

markings. A long stretch of the mare lies along the southern part of the crater. There is also a smaller section near the western rim. Prior to formal naming in 1970 by the

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

, the crater was known as ''Basin XVI''. File:Apollo basin topo.jpg, Topographic map File:Apollo basin GRAIL gravity.jpg, Gravity map based on

GRAIL The Gravity Recovery and Interior Laboratory (GRAIL) was an American lunar science mission in NASA's Discovery Program which used high-quality gravitational field mapping of the Moon to determine its interior structure. The two small spacecraf ...

Interior craters

Three craters are named after the crew of

Apollo 8 Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave low Earth orbit and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing, and then departed safely back to Earth. These ...

. In the southeast part of Apollo is

Borman Borman is a surname. Notable people with the surname include: * Danleigh Borman (born 1985), South African soccer player *Frank Borman (1928–2023), American astronaut **The Frank Borman Expressway in Indiana named after him * Geoffrey D. Borman, ...

crater, named after commander

Frank Borman Frank Frederick Borman II (born March 14, 1928) is a retired United States Air Force (USAF) colonel, aeronautical engineer, test pilot, businessman, and NASA astronaut. He was the commander of Apollo 8, the first mission to fly around the Moo ...

. Near the southeastern margin of Apollo is

crater, named after

William Anders William Alison Anders (born 17 October 1933) is a retired United States Air Force (USAF) major general, former electrical engineer, nuclear engineer, NASA astronaut, and businessman. In December 1968, he was a member of the crew of Apollo 8, ...

. On the eastern margin is Lovell crater, named after

Jim Lovell James Arthur Lovell Jr. (; born March 25, 1928) is an American retired astronaut, naval aviator, test pilot and mechanical engineer. In 1968, as command module pilot of Apollo 8, he became, with Frank Borman and William Anders, one of th ...

. Many craters within and adjacent to the Apollo impact have been named to honor deceased NASA employees.

Dryden '' John Dryden (; – ) was an English poet, literary critic, translator, and playwright who in 1668 was appointed England's first Poet Laureate. He is seen as dominating the literary life of Restoration England to such a point that the peri ...

is attached to the west-northwestern exterior of the inner ring. Chaffee is a similar-sized crater that lies partly across the southwest section of the inner ring. Inside the inner ring are the craters Resnik, McAuliffe and Onizuka, and the Jarvis– McNair crater pair. The crater

Smith Smith may refer to: People * Metalsmith, or simply smith, a craftsman fashioning tools or works of art out of various metals * Smith (given name) * Smith (surname), a family name originating in England, Scotland and Ireland ** List of people wi ...

lies across the northern part of the inner ring. In 2006 the IAU approved a proposal to name seven interior craters to honor the astronauts killed in the Space Shuttle ''Columbia'' disaster. Three of the crater names include the respective astronaut's first initials to distinguish them from the existing craters called

Anderson Anderson or Andersson may refer to: Companies * Anderson (Carriage), a company that manufactured automobiles from 1907 to 1910 * Anderson Electric, an early 20th-century electric car * Anderson Greenwood, an industrial manufacturer * Anderson ...

Brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model us ...

and

Clark Clark is an English language surname, ultimately derived from the Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone who was educate ...

References

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External links

* {{Craters on the Moon: C-F Impact craters on the Moon Apollo program